The story of the cortex and the limbic
Mammals evolved from reptiles by learning to live in groups. They didn’t consciously choose that, of course. Individuals who stuck near others simply had higher survival rates, so natural selection created a brain that sought social alliances.
Mammals pay a high price for the security of the group. They submit to dominators to avoid injury. Wild chimpanzees are often missing a finger or an ear lobe due to conflict with a troop-mate. Yet mammals stick with their herd or pack or troop. People tend to cheat when they see others are doing it. Your mammal brain feels safe when it’s with a herd. If the herd starts endangering itself, your human cortex can inhibit your mammalian urge to merge. In fact, that’s why you have all those extra neurons. to end up in the jaws of a predator if they leave. They evolved brains adept at avoiding conflict.
We have inherited the limbic system that all mammals have in common. It releases happy neurochemicals when survival prospects improve, and icky neurochemicals when survival prospects are threatened. Contemplate isolation or conflict and those icky chemicals flow. Remain in secure social alliances and happy chemicals flow.
Your mammal brain is not on speaking terms with your cortex because it doesn’t process language. Your limbic system doesn’t tell you in words why it triggers neurochemical ups and downs. But it is always busy scanning the world for threats and opportunities to help you survive.
Every mammal has a cortex hooked up to its limbic system. The cortex is tiny in sheep and rodents, so their capacity to adjust old impulses to new information is tiny. They follow the herd and submit to avoid conflict because it feels good. Primates, by contrast, have a large cortex. They can inhibit impulses when experience proves it’s in their survival interest. The primate brain is always analyzing new information and deciding whether to dominate or submit, whether to follow or take initiative.
Your cortex is three times as large as a chimpanzee’s. You can bring a lot of information to bear on your social choices. Sometimes you see that honoring the mammalian impulse to avoid conflict and follow the group is your best option. Other times you see reason to go it alone and resist submitting.
Analyzing social dynamics at every moment is stressful. It would be nice have one principle to guide every situation. But your ancestors evolved extra neurons because social analyzing promotes survival. You inherited all those neurons to make survival judgements for yourself instead of just doing what everybody does. When you need to escape a herd that seems bound for harm, it’s good to know your brain evolved for just that challenge!
We’re all equal in the abstract, but the mammalian part of your brain does not process abstractions. It continually compares your strength to others to protect your hunt from being swiped and leaving you hungry. We’re equal with our cortex, but our mammal brain experiences the world as constant ups and downs, no matter where you are in life. Kings agonized about rivals and Pharaohs agonized about death. Presidents agonize about press coverage and superstars agonize about…everything. When you feel on top, the good feeling soon passes and your brain looks for ways to triumph again.
Your cortex is not on speaking terms with the primitive limbic brain that controls your neurochemistry because the limbic system does not use words or abstractions. Our limbic brain is inherited from earlier mammals and responds to the world with this simple formula: release happy chemicals when something is good for survival, and unhappy chemicals when something is bad for survival. Survival means different things to your cortex and your limbic system because your cortex learns from experience while your limbic system evolved to meet the needs of your ancestors.
Related
Cooperate with each other to maximise their reproductive success
According to a recent research paper published by the Journal of Animal Ecology, groups of male dolphins who put aside their sexual competitiveness and form alliances with each other to seek out and reproduce with females have better reproductive success than males who go it alone. “These results are fascinating because it demonstrates that male bottlenose dolphins need to cooperate with each other to maximise their reproductive success,” says Wiszniewski.
Our mammalian limbic brains - Happiness and survival are intertwingled
Your happy chemicals evolved to ebb and flow. But if you attend to this feeling that something is wrong, it can preoccupy you. Your cortex will scan the environment for evidence that something is, in fact, wrong. And it will find evidence to confirm that feeling
Status is who we are - our mammalian origins
Your human cortex specializes in learning from experience, while your mammalian brain specializes in motivating you with good and bad feelings
The bigger a mammal’s cortex, the more it is able to forgo immediate rewards in pursuit of longer-term rewards, such as social alliances that raise its status.
Group selection might explain the evolution of biological altruism
Altruism is only locally disadvantageous
The neuroscience of decision-making and learning
The limbic brain needs to be in active relationship with others to be happy
Where does altruism fit into this…mammals seek dominance because the serotonin feels good
